[Amps] HV Switch Mode Power Supplies

[W0UN -- John Brosnahan]

 >
 >I'd personally not buy something like that without seeing some
 >guaranteed specifications - including load reguation and noise.
 >The specs are
 >http://wattsunlimited.com/_wsn/page2.htm
 >are poor, both in the way presented and their values.
 >
 >I can't help feeling that is poorly designed. As I said earlier,
 >designing that sort of thing is not trivual, but to me at least that is
 >poorly designed.
 >
 >David Kirkby,
 >G8WRB




Hi, David--

Just FYI.  Watts Unlimited is owned by W9QQ who has a PhD in
electrical engineering and has designed many SMPSs.  Granted,
this design is a "gutless wonder" and it bears no resemblance to
some of the TV transmitter SMPSs that he has designed.  He
has sent me some schematics (many years ago) of some "serious"
SMPSs, so I know he knows what he is doing.

I think he designed up this gutless wonder because that is what
hams want and can afford.  It may not be ideal, but it works, it is
cheap, and it is light weight.

I have the same reaction to this supply as I do to some of the cheaper
ham amps (of course, I am biased -- having been president of Alpha/Power
for three years) but this SMPS demonstrates a minimalist approach
and without complex feedback it is something that one can troubleshoot
in the field with minimal test equipment and knowledge.  MFJ has been
successful with the same approach to marketing.

73--John  W0UN

----------------------------------------------------------------
 From the W9QQ file on eham.net/callbook

W9QQ's name is Tim. He was first licensed with the Novice Class call, WN9MIJ in
1954 while twelve years of age. He obtained the Conditional Class license the
following year and retained W9MIJ until 1975. Other calls held include V47QQ
(1989 CQWWDX Contest), KG4QQ (1991 CQWWDX Contest), HL9QQ in 1987, and PJ9Q
(1997 CQWWDX Contest). He has also operated from BY4AA and HZ1HZ in 1994.

Tim is a 1964 graduate of the U.S. Naval Academy and served on active duty as
an Engineering Duty Officer until 1975. He retired from the Naval Service with
eleven active and eighteen reserve years in 1993. All of this time, Tim was
active on-the-air with DX being the main interest. He has been /mm from several
US Navy Ships in the 1960s.

Tim received the Naval Engineer Degree and the SM Degree in Nuclear Engineering
from MIT in 1969, attending under Navy orders. He returned to graduate school
in 1972 receiving the Ph.D. in Electrical Engineering from Old Dominion
University in 1977. Since that time and until 1984 he was engaged in a career
designing and managing the design of AM, FM, TV and SW broadcast transmitters
at Harris Broadcast Products Division, Quincy IL. He had a one year tour at
Voice-of-America as Chief of Broadcast Systems Engineering in 1985, then went
on as Vice-President, Engineering at Acrodyne Industries, Inc. of Blue Bell,
PA, one of the leading suppliers of television broadcast transmitting
equipment. Tim is currently a consulting engineer to Techtrol Cyclonetics, Inc.
in New Cumberland, PA. He is a former member of the Board of Directors for
Emcee Broadcast Products, Inc. of White Haven, PA.

Tim holds nine U.S. patents, with six others applied for in the field of TV
broadcast transmitters, one in the field of electric lighting control and is a
Life member of ARRL and a Fellow of the IEEE. Over the years he has accumulated
three Cover Plaque Awards from QST and has written many technical articles for
QST, QEX and CQ. He has also written for Broadcast Engineering, RF Design,
World Broadcast News, TV Broadcast, The National Association of Broadcasters,
the Society of Broadcast Engineers and others. He also contributed a chapter to
The Electronics Handbook, CRC Press, Jerry C. Whitaker, Editor-in-Chief, 1996
and a chapter to Semi-Conductor Devices and Circuits, CRC Press, Jerry C.
Whitaker, Editor, 2000.

His main amateur radio interest is DX with 5BDXCC #556 and is at the top of the
Honor Roll with 354, missing only BS7. He also has 210 countries confirmed on
phone/mobile including real exotics such as BY, BV and JT. Recently, he has
added PSK31 to his mobile activities while on business trips operating from
hotel (motel) parking lots chasing DX into the late night hours. (See QST March
2000 page 55).